Multifunction Calibrators include two or more of the following: temperature, pressure, frequency, signal, HART capability. Save money as well as space in the toolbox by purchasing one instrument with multiple functions. Functions of temperature, pressure, and voltage/mA signals are discussed at length here Products > Process / Calibration

Following is a discussion on HART Communications

What is a HART Communicator vs. HART Multifunction Calibrator? And what is HART anyway?

HART is a digital communications signal riding on top of a 4-20 mA signal, short for Highway Addressable Remote Transmitter. It was developed by Emerson Process/Rosemount and later made public, so now all major instrument manufacturers support the standard. You may see other protocols such as Fieldbus (more popular in Europe), CANBUS (popular in automotive and production line manufacturing), BRAIN (proprietary to Yokogawa), but HART is the king in process instrumentation. Smart pressure transmitters, temperature transmitters, flowmeters, and other instruments with HART capability give access to anyone with a HART communicator to basic to advanced configuration parameters. Setting up ranges, units of measure, tag labels, input filter/dampening, square root extraction of differential flow measurement devices like orifice plates are all possible remotely from anywhere on the 4-20 mA loop. Hazardous area transmitters become much less expensive because keypads or alternate interfaces suitable for use in explosive atmospheres are not needed.

A HART Communicator is used to communicate with the transmitter. Emerson still makes them, model 475, which we carry at TEquipment. We also carry Meriam’s MFC HART Communicator. A HART Communicator is not a calibrator. Re-ranging the URV and LRV (upper and lower range values) of a transmitter is not calibrating. A HART Multifunction Calibrator has the capabilities of a HART Communicator and a multifunction calibrator may also store the measuring instrument configuration files.

FAQ: Can I get a NIST certificate for my HART Communicator?
Answer: No, but you can get one for a HART Multifunction Calibrator.
A HART Communicator is an instrument configuration tool like a universal TV remote can be configured to operate your TV. Stored in memory are device specific drivers so it can communicate with over a thousand registered instruments.

HART protocol has a standard set of menus, so basic tasks can be performed and thousands of instruments use them. If you need to drill deep into a very specific capability of your instrument, then you will need its device driver (DD). The HART Communication Foundation now maintains this list and any HART Communicator or Multifunction Calibrator manufacturer will install the latest set when you purchase. These do not change frequently, but it is always a good idea to get the option for 3 years of no charge upgrades for the Emerson 475 HART Communicator. Hart Multifunction Calibrators from Fluke as of this writing are no charge downloads to update the device firmware. Martel Electronics makes a HART Multifunction Calibrator too, but it has loaded only the basic/universal HART commands so upgrades are not needed. Meriam’s MFC HART Communicator and HART Multifunction Calibrator as of this writing include at least 3 years of upgrades at no charge. If you will be using more than just the basic commands, then regardless of model, do check the supported devices list before purchase.